PROCESS FOR OBTAINING A SYNTHETIC OFFRETITE OF HIGH SILICA CONTENT AND USE THEREOF TO PRODUCE HYDROCARBONS OF HIGH LIGHT OKEFINS CONTENT BY CONVERSION OF METHANOL AND/OR OF DIMETHYLETHER

摘要

1. Offretite whose characteristics are : - SiO2 /Al2 O3 molar ratio higher than 30 - vectora and vectorc crystalline parameters respectively ranging from 1.285 to 1.310 nm for a vectora and from 0.748 to 0.755 nm for a vectorc - potassium content lower than 1 % by weight - benzene adsorption capacity at 25 degrees C, under a partial pressure of 70 torrs (70 x 133.32 Pa), higher than 5 % by wieght, - a secondary microporosity ranging from 3 to 5 nm and corresponding to about 5-50 % of the total pore volume of the zeolite of offretite structure.